Unraveling Hidden Physics in Multiphase Combustion: Preferential Vaporization at Elevated Pressure

运输液体燃料，如汽油、喷气燃料和柴油燃料，包含数百种分子，它们的大小和化学结构变化很大。因此，液体燃料的燃烧涉及到燃料中各种分子和喷雾大小分布所决定的化学反应速率之间的复杂耦合。该项目的主要目的是建立燃料汽化过程的基本知识，特别是在内燃机应用的高压条件下。该项目的成果将为开发下一代先进内燃机提供基础，从而减少排放并提高整体效率。该项目还将包括重要的教育活动，包括研究生和本科生的研究项目，以及面向当地高中学生和教师的推广项目，以完成国家科学基金的使命。该项目将培养下一代美国能源和工程科学领域的创新者。该研究的目标是通过在高压条件下设计和执行定义良好的实验来建立优先汽化影响的基础知识，这些实验将用于验证和评估优先汽化子模型的保真度。本项目将完成三个实验任务和一个建模任务：1)多组分燃料分离单液滴汽化的实验表征；2)孤立单液滴与火焰相互作用的实验研究；3)用定义良好的多组分燃料混合物控制燃料汽化程度的近极限燃烧行为实验；4)能够描述优先汽化特性的喷雾子模型的开发和验证。该项目的研究结果有望为替代燃料及其合成方法的发展提供有见地的指导，并为制定先进的燃料规格协议奠定基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Transportation liquid fuels, such as gasoline, jet, and diesel fuels, contain hundreds of molecules with wide variations in their sizes and chemical structures. Consequently, the combustion of liquid fuels involves complex coupling between chemical reaction rates dictated by various molecules in the fuel and spray size distribution. The principal aim of this project is to establish fundamental knowledge of the fuel vaporization process, particularly at high-pressure conditions relevant to the applications of internal combustion engines. The outcomes of the project will provide a fundamental foundation for developing next-generation advanced combustion engines, allowing the reduction in emission as well as increase overall efficiency. The project will also encompass significant educational activities, including both graduate and undergraduate research programs and an outreach program geared towards local high school students and teachers to fulfill the mission of the NSF. The project will allow nurturing of the next generation of U.S. innovators in energy and engineering sciences. The goal of the proposed research is to establish fundamental knowledge of preferential vaporization impacts by designing and performing well-defined experiments at elevated pressure conditions, which will be used for validating and evaluating the fidelity of the sub-model of preferential vaporization. The project will perform three experimental tasks and one modeling task: 1) Experimental characterization of isolated single droplet vaporization for multi-component fuels; 2) Experimental investigation of isolated single droplet interaction with flames; 3) Experiments on near-limit combustion behaviors by controlling the extent of fuel vaporization with well-defined multi-component fuel mixtures; 4) Development and validation of spray sub-model capable of describing preferential vaporization characteristics. The results of this project are expected to provide insightful guidance to the development of alternative fuels and their synthetic methodologies and a fundamental foundation to develop advanced fuel specification protocol.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.